Electric-arc lamp



Patented Sept. 27, I898.

u. 6H,460. I

T." H. PETTENGILL.

ELECTRIC ARC LAMP.

(Application filed Sept. 4, 1897.)

2 Sheets-Sheet I.

(No Model.)

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No. 6l|,460. Patented Sept. 27, I898. T. H. PETTENGlLL.

ELECTRIC ARC LAMP.

(Application filed Sept. 4, 1891) (No Model.) 2 Sheets-Sheet 2.

V A :l V v 7 UNITED STATES Pnnnr Orrrone TIMOTHY H. PETTENGILL, OF AMSTERDAM, NEW YORK.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 611,460, dated September 27, 1898.

Application filed September 1897. Serial No. 650,641. (No model.)

To aZZ whom, it may concern.-

Be it known that I, TIMOTHY H. PETTEN- GILL, a citizen of the United States, residing at Amsterdam, in the county of Montgomery and State of New York, have invented certain new and useful Improvements in Arc- Lamps; and I .do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates generally to ringclutch feeds for arc-lamps, and particularly to the feed mechanism of those double-carbon arc-lamps commonly known to the trade as the Thomson-Houston or T-H.

In the common form of double-carbon T- H arc-lamp there is employed what is known as a transfer-lever, which is designed to prevent the second pair of carbons from burning until the first pair is entirely consumed and to insure the maintenance of the arc of the second pair of carbons at the same voltage as that of the are previously maintained between the carbons of the first pair. In this type of arc-lamp independent clutches are employed for the two upper-carbon carriers, both clutches being carried by and adapted to move with the armature of the electromag- 7 net, and the clutch for the second pair of carbons is hung from one end of the transfer-lever in such a manner that while the first pair of carbons are burning and the armature vibrating said clutch will impart a rocking movement to the transfer-lever without being tripped, and the upper carbon of the second pair is held too high for the establishment of an arc between it and the lower carbon. The continued consumption and downward feed of the upper carbon of the first pair eventually causes the head on the upper end of its carbon-carrier to rest on the free end of the transfer-lever, so that the weight of said upper carbon and its carrier is removed from its clutch, and hence from the armature, and transferred to the transfer-lever. This causes the arc to lengthen, and by reason of the increased resistance the current strength in the magnet increases and the continued attraction of the armature occasions the tripping of the clutch of the second pair of carbons and the establishment of an arc between them, because the transfer-lever being weighted by the carbon-carrier of the first paircannot fol low the oscillations of the armature as before.

One of the principal objections to the T-II lamp is its liability of complete extinguishment, which will result upon the sticking of the feed-carbon of the first pair, for it will be clear that if the uppermost carbon of the first set should fail to feed properly the arc would be extinguished and the transferlever would remain free to rock with the second clutch, so that the second pair of carbons would not burn and the lamp would be useless.

While the transfer-lever is intended to insure the maintenance of the second arc at the same voltage as the first arc, in practice the voltage necessary to maintain the are between the second pair of carbons is somewhat higher than that necessary for the maintenance of the first arc. Ordinarily it requires the same magnetic force to trip one clutch as it does the other; but when the uppermost carbon-carrier on the first side is resting on the transfer-lever its weight is removed from its clutch, and hence from the vertically-movable spring-retracted armature, and transferred to the transfer-lever. The removal of this weight from the armature and the additional resistance offered to the movement of the transfer-lever by the weighting thereof necessitates a proportionately greater magnetic attraction (and consequently a higher voltage) to overcome the armature-retracting spring and to exert sufficient pressure on the second clutch'to trip the same, so that the maintenance of the are between the members of the second set of carbons requires a higher voltage than is necessary to maintain the are between the carbons of the first pair.

The'present invention is designed to overcome the above-mentioned faults in T-H lamps, and this is accomplished by dispensing entirely with the transfer-lever and employing carbon-rod clutches of improved construction and arrangement. Described more in detail, each clutch consists of a suspendingrod, which is pivoted to the armature and which is extended above the latter and there equipped with a stop adapted to engage the cap of the carbon-carrier,ahead at the lower end of the rod, through which the carbon-carrier loosely passes, and a ring-clutch lever pivotally and detachably connected to the head and equipped with a trip-screw at its free end. The construction is such that the feed is sensitive, easy, and regular, and sudden dropping and bumping of the carbons entirely obviated, while the parts subjected to wear can be quickly and easily removed and others substituted. The trip-screw of the second clutch is set to trip somewhat later than the first clutch, and hence the second set of carbons will not feed until the first set is consumed. If, however, the rod of the first set should stick in the bushings and fail to feed, its clutch is tripped when the armature reaches the feeding-point and the weight of the rod is removed from the armature, and by reason of the lengthened arc the magnetic attraction increases until the second clutch is tripped, whereupon an arc is established between the carbons of the second set. I thus overcome the fault of extinguishment of the lamp by reason of the sticking of the feedcarbon on the first side, although it is true in this particular instance the second arc established would require a slightly-higher voltage than did the first arc. If the carbon sticks in its clutch, however, its weight still remaining on the armature, the second arc will burn at the same voltage as did the first arc, and if the stuck carbon should afterward become released the arc will be extinguished on the second side and reestablished between the carbons of the first pair. When the carbons of the first set are entirely consumed, the upper-carbon carrier rests on the screw at the upper end of the suspendingrod of its clutch and will then be supported by and follow the movements of the armature or rocker, and the current having shifted to the second set of carbons the arc will be established and maintained between them at a voltage which is somewhat lower than that which was used for the first arc, and it is herein that my invention effects a saving of energy. The reason is that the weight of the carbon-carrier having been removed from its clutch no pressure is required to trip said clutch, and as the second clutch is set to trip when the armature is nearer to the pole-pieces of its magnet than previously the current strength necessary to attract the armature in its then position with the same force as before is less. Consequently the arc is maintained at a lower voltage during the latter half of the night and is brightest during the first half, which is of course desirable. The construction of the clutch will be set forth in detail hereinafter. I

In the accompanying drawings, Figure 1 represents a side elevation of my improved clutch applied to a carbon-carrier. Fig. 2 is a detail View of the ordinary form of tubular carbon-carrier. Fig. 3 is a detail perspective view of the hanger. Fig. 4 is a similar view of the ring-clutch. Fig. 5 is a side elevation of a T-H double-carbon arc-lamp, certain parts only being shown, equipped with my improved clutch mechanisms; and Fig. 6 is a vertical section thereof, taken in front of the carbon-carriers and clutches.

A designates an upper-carbon carrier, such as commonly used in arc-lamps, and a the ordinary form of enlarged cap or button which is screwed into its upper end.

The hanger of my improved clutch is composed of a straight suspending-rod B and a head 0, connected to the lower end of the rod, the head having a depending ear diametrically opposite the suspending-rod provided with an aperture 0 and an opening through which the carbou-carrier loosely passes. The suspending-rod extends alongside of and parallel to the carbon-carrier and is flattened at its upper end, where it is pierced with an aperture n, which receives a screw that pivots it to the rocker or armature N, which is oscillated by the usual electromagnet. The rod extends above the rocker and a carbon-carrier catch-screw D is threaded therethrough in a position for its tip to engage the under face of the cap a when the carbon has been consumed and its carrier descended sufficiently far.

I employ a ring-clutch E of lever shape, whose ring is of greater diameter than that of the carbon-carrier, and said ring-clutch has a tapered and slightly-curved end J, which is loosely fitted in the aperture 0 to enable the clutch to have the necessary up-and-down play to insure the proper grip and release of the carbon-carrier. A thumb-ad j ustin g tripscrew S is threaded through the other end of the ring-clutch in a vertical direction, and its tip is adapted to rest on the lamp-frame L and release the clutch when the carbon-carrier has descended sufficiently far.

The operation is as follows: lVhen the arc lengthens and the carbon-carrier is forced downwardly by the armature, the tip of screw S strikes the lamp-frame L, lifting the ringclutch and releasing the carbon-carrier, which then slips through the clutch by gravity until the armature-retracting spring reasserts itself and lifts the hanger, whereupon the free end of the ring-clutch drops (the screw S being raised above the lamp-frame) and the latter again grips the carbon-carrier.

The only part of the device which is sub jected to any great wear is the ring-clutch, and it only has to be replaced, the hanger and screws having an indefinite length of life. It is to be observed that no pivot-pin or rivet is employed in hanging the ring-clutch to the head, the connection being a detachable one, and hence removal and replacement of the ring-clutch can be had without using tools of any kind. By disposing the suspending-rod diametrically opposite the fulcrum of the ring-clutch it is made possible to bring the point of suspension of the clutch and the fulcrum thereof very close to the carbon-carrier, giving a compact construction which permits the employment of a ringclutch of considerable length and rendering the device very sensitive, insuring an even sliding and feed, thereby avoiding any sudden jumping of the carbon, with the consequent flickering of the arc and the greater consumption of the carbons.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In an arc-lamp feed mechanism, the combination with a suspending-rod adapted for connection to the armature or rocker, of a head secured to said rod having an opening for the loose reception of the carbon-carrier, and provided with an apert-ured ear diametrically located in relation to the suspendingrod, a ring-clutch having one end loosely received in the apertured ear and an adjusting trip-screw carried by the free end of the ringclutch and adapted to engage the lamp-frame when lowered sufficiently.

2. In an arc-lamp feed mechanism, the combination with an armature or rocker, and a carbon-carrier, of a suspending-rod depending from the armature closely adjacent to the carbon-carrier, a head secured to the lower end of the suspending-rod which has an enlarged opening through which the carboncarrier passes, and is provided with a depending apertured ear located on the opposite side of the carbon-carrier from the suspending-rod, a ring-clutch having a rounded end which is loosely received in the aperture of the car, an adjusting thumb-trip screw-threaded through the other end of the ring-clutch and diametrically opposite the ear, and a checknut for said screw, substantially as described.

3. In an arc-lamp feed mechanism, the combination with a rocker or armature, and a carbon-carrier having a stop, of a suspendin g-rod connected to armature and having its upper end extended above the latter in position to engage the stop when the carbon has been consumed, and a carbon-carrier clutch carried by the suspending-rod.

4:. In an arc-lamp feed mechanism, the combination with a rocker or armature and a carbon-carrier having a stop, of a suspending-rod connected to the armature and having its upper end extended above the latter, a catch screw threaded through said extended upper end in position to engage the stop when the carbon has been consumed and a carboncarrier clutch carried by the lower end of the suspending-rod.

5. In a double-carbon arc-lamp, the combination with an electromagnet, an armature therefor, and independent movable carbonholders each carrying a stop device, of independent clutch mechanisms, for the respective carbon-holders, each clutch mechanism comprising a suspending-rod hung from the armature and having an upward extension constituting a stop, and a carbon holder clutch carried by the suspending-rod; the construction and arrangement of said parts being such that a carbon-holder clutch of one clutch mechanism is inactive when the other carbon-holder clutch is in operation, and the stop devices on the respective carbon-holders are arrested by the upward extensions on the suspending-rods of the clutch mechanisms when the carbons carried by said holders have been consumed, whereby, during the operation of the lamp, first one carbon-holder and then the other is directly suspended from the armature and the weight of both carbonholders is always borne by the armature.

In testimony whereof I aflix my signature in presence of two witnesses.

TIMOTHY H. PETTENGILL.

\Vitnesses:

JOSIAH SUrrs, JOHN E. HEWITT. 

